Does stress make hair gray?

Legend has it that in 1791, Marie Antoinette, wife of French King Louis XVI, had her hair turned white overnight before being sent to the guillotine
.

However, the legend may not be accurate.
Studies have shown that hair that has grown from the follicle does not change its color
.
Researchers from Columbia University’s Vagros School of Internal Medicine and Surgery have provided the first quantitative evidence between psychological stress and people’s graying in a new study published in eLife

Stress will accelerate hair graying, which seems to be an intuition, but the researchers unexpectedly discovered that when the stress is removed, the color of the hair can be restored
.
This finding contrasts with a recent study on rats that showed that gray hair caused by stress is permanent

The new study has broader implications than confirming the old speculations about the effect of stress on hair color, said Martin Picard, the study's author and associate professor of behavioral medicine at Columbia University's Vagros School of Surgery
.
"Understanding the mechanism that allows the'aged' gray hair to restore the'young' pigment state can provide new clues for the malleability of human aging and how stress affects it

"More and more evidence shows that human aging is not a linear, fixed biological process, but at least to a certain extent may be prevented or even temporarily reversed.

Gray hair, a platform for research on aging

He said that just like the annual rings of a tree trunk preserve the life information of a tree over the past few decades, people's hair also contains personal biological history information
.
When the hair is still located under the skin as a follicle, it is affected by stress hormones and other things happening in the mind and body

It has long been believed that psychological stress will accelerate hair graying, but scientists have been arguing about this connection
.
At present, there is still a lack of sensitive methods that can accurately associate the pressure time with the pigmentation of the hair in a single follicle

Study lead author Ayelet Rosenberg, a graduate student in Picard's lab, has developed a new method that captures highly detailed images of small human hair slices to quantify the degree of pigment loss (whitening) in each slice
.
Each piece is about 1/20 mm wide, representing hair growth for about 1 hour

"If you look at a hair with your eyes, it always seems to be the same color, unless there is a major shift
.
" Picard said, "but with a high-resolution scanner, you can see tiny color changes, This is what we measured

The researchers analyzed the hair of 14 volunteers and compared the results with each volunteer's stress diary
.
In the diary, the volunteers were asked to review what happened during the day and rate their stress levels each week
.

Picard said investigators have noticed that some gray hair will naturally return to its original color, which is an unprecedented quantitative record
.

Shannon Rausser, the second author of the paper and another student in the Picard lab, said that when comparing hair with a stress diary, he found a surprising correlation between stress and hair graying.
In some cases, with stress After the release of the hair, the trend of whitening hair has been reversed
.

"A person went on vacation.
During the vacation, the five hairs on this person's head turned black, showing time synchronization
.
" Picard gave an example
.

Brain mitochondria are the "culprit"

To better understand how stress causes gray hair, the researchers also measured the levels of thousands of proteins in the hair and how the protein levels change with the length of each hair
.

When the hair color changes, 300 proteins change, and the researchers developed a mathematical model showing that stress-induced changes in mitochondria may explain how stress makes hair gray
.

"We often hear that mitochondria are the power source of cells, but this is not their only role
.
" Picard said, "Mitochondria are actually like tiny antennae in cells, responding to a variety of different signals, including psychological stress.

.
"

This mitochondrial link between stress and hair color is different from what was recently discovered in another mouse study
.
The study found that hair graying caused by stress is caused by the irreversible loss of hair follicle stem cells
.

"Our data show that the whitening of human hair is reversible, which means a different mechanism
.
" said Ralf Paus, a professor of dermatology at the University of Miami’s Miller School of Medicine and co-author of the paper
.
"Mice have very different hair follicle biology.
This may be an example of how the findings in mice cannot be applied well to humans
.
"

Not everyone can go back to black

Reducing the stress in life is a good goal, but it does not necessarily make your hair a normal color
.

"According to the mathematical model, we believe that the hair needs to reach a threshold before it turns white
.
" Picard said, "In middle age, when the hair is close to this threshold due to physiological age and other factors, pressure will push it to this threshold and then change.
White hair
.
"

"But we don't think that alleviating the stress of a 70-year-old man with gray hair for many years can make their hair black, or increasing the stress of a 10-year-old child is enough to make their hair exceed the gray hair threshold
.
" (Source: China Science News Feng Lifei)

Related paper information: https://doi.
org/ 10.
7554/eLife.
67437